Map display device and program therefor

ABSTRACT

An object of the present invention is to provide a map display device that makes full use of historic records of the input addresses of previously retrieved points, thereby simplifying the process for inputting an address of a point near a previously retrieved point and thereby facilitating easy point retrieval. The map display device for retrieving a point at an input address and for displaying a map that covers the retrieved point includes storage means for storing historic records of the input addresses of the previously retrieved points in a hierarchy of administrative district levels, and a control means for displaying an input page through which an address is input on an administrative hierarchical basis as well as for displaying an administrative district name of a previously retrieved point as a hierarchy of administrative levels or item fields.

[0001] The disclosure of Japanese Patent Application No. 2002-349216filed on Nov. 29, 2002 including the specification, drawings andabstract are incorporated herein by reference in their entirety.

CROSS-REFERENCE TO RELATED APPLICATION

[0002] This application claims, under 35 USC 119, priority of JapaneseApplication No. 2002-349216 filed Nov. 29, 2002.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] The present invention relates to a map display device and to aprogram therefor.

[0005] 2. Description of the Related Art

[0006] Conventional vehicle map display devices (navigation devices)allow a destination to be set by input of an address. Some conventionalmap display devices retrieve a destination by inputting an address ofthe destination as a hierarchical series of inputs, i.e., on anadministrative district-to-district basis in decreasing order ofdistrict size, for example: Administrative divisions of Japan (the Tokyometropolitan area, Hokkaido, and other prefectures) → Municipalities(Cities, Wards, Towns and Villages) → Large hamlets (“Ooaza”-a largecollection of dwellings) → Small hamlets (“Koaza”-a small collection ofdwellings) → House number. Every inputted address of a retrieved pointis stored as a historic record of past inputted addresses. The historicrecord of the inputted addresses of previously retrieved points arepresented to the user in the form of a list. This list simplifies theprocess of point retrieval where the user wishes to retrieve a pointpreviously retrieved.

[0007] U.S. Pat. No. 5,819,200 discloses a map display device whichallows the user to retrieve a point slightly distanced from a previouslyretrieved point having an address listed in the historic record ofinputted addresses of the previously retrieved points. In this prior artsystem the point closest to his/her desired point is selected from thelist, and a scrollable map that covers the desired point is displayed.

[0008] For retrieving a new point, the conventional map display devicerequires the user to input an address of the new point on anadministrative district-to-district basis; from the broadestadministrative division down to a house number. In other words, the usermust input an address on a different input display (page) for each levelof the hierarchy of addresses. This is time-consuming and bothersome.This problem becomes worse when the new point has an address similar tothe address of a previously retrieved point. Regardless of thesimilarity between the address of the new point and the address of apreviously retrieved point, the conventional map display device requiresthe user to input the address of the new point from the beginning byselecting each administrative district in decreasing order of districtsize, which is wasteful of the user's time.

SUMMARY OF THE INVENTION

[0009] In order to solve the foregoing problems, the present inventionprovides a map display device that makes full use of the historicrecords of the inputted addresses of the previously retrieved points andwhich simplifies the inputting of an address of a point located near thepreviously retrieved point, thereby facilitating point retrieval.

[0010] Accordingly, the present invention provides a map display devicefor retrieving a point at an inputted address and for displaying a mapthat covers the point retrieved for the inputted address, comprising:storage means for storing historic records of the inputted addresses ofpreviously retrieved points in a hierarchy, i.e., on differentadministrative levels (administrative district-to-district basis); andcontrol means for displaying an input page by which an address is inputas a series of inputs in a hierarchical order, i.e., on anadministrative district-to-district basis, and for displaying anadministrative district name of a previously retrieved point at eachlevel of the hierarchy as an administrative district item field.

[0011] Further, according to the present invention, there is another mapdisplay device for retrieving a point at an inputted address and fordisplaying a map that covers that retrieved point, comprising: storagemeans for storing information about the retrieved point; and controlmeans for reading out historic records of the inputted addresses ofpreviously retrieved points and for displaying them in the form of alist, wherein the address of the previously retrieved point is selectedfrom the list and displayed in a Japanese syllables input page, and apreviously retrieved point whose address was is in Japanese syllablesusing the input page.

[0012] Further, according to the present invention, there is provided amachine-readable medium encoded with a program for a map display devicefor retrieving a point at an inputted address and for displaying a mapthat covers the point retrieved for the inputted address, and encodedwith historic records of the previously input addresses for retrievedpoints, arranged in a hierarchy of administrative district levels,wherein the program includes:

[0013] displaying an input page, presenting an administrative districtname of a previously retrieved point as an administrative district itemfield, for input of an address as a hierarchy administrative districtsat different levels.

[0014] In another embodiment the present invention provides amachine-readable medium encoded with a program for a map display devicefor retrieving a point at an inputted address and for displaying a mapthat covers the point retrieved for the inputted address and encodinginformation for the retrieved point, wherein the program includes:

[0015] retrieving historic records of input addresses of previouslyretrieved points;

[0016] displaying the retrieved historic records in the form of a listfor selection of an address of a previously retrieved point from thelist; and

[0017] displayed a Japanese syllables input page, and further thereonthe past-retrieved point whose selected address was set in the Japanesesyllables input page is retrieved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a block diagram of a map display device according to apreferred embodiment of the present invention.

[0019]FIG. 2 illustrates an input page used in the embodiment of FIG. 1.

[0020]FIG. 3 is a flowchart of a process of point retrieval based onaddresses according to the embodiment of FIG. 1.

[0021]FIG. 4 is a flowchart of a process for inputting an address of apoint to be retrieved according to the preferred embodiment of FIG. 1.

[0022]FIG. 5 shows a historic record of seven previously inputtedaddresses arranged in a hierarchy of five or six administrative levels.

[0023]FIG. 6 illustrates the structure of the data for the historicrecords of the inputted addresses of the previously retrieved pointsshown in FIG. 5.

[0024]FIG. 7 is a flowchart of a process for inputting an address of apoint to be retrieved based on the data structure shown in FIG. 6.

[0025]FIG. 8 is a block diagram illustrating data-portability betweendifferent systems by deriving address information from data importedfrom other systems.

[0026]FIG. 9 is a flowchart of another process for point retrieval basedon addresses, in accordance with the preferred embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Preferred embodiments of the present invention will now bedescribed in detail with reference to the accompanying drawings.

[0028]FIG. 1 shows a preferred map display device as comprising: aninput unit 1 which serves as selection means for inputting information,such as a departure point, a destination point, or the like, necessaryfor route guidance; a present position detection unit 2 for detectingpresent position of the vehicle; an information storage unit 3 forstoring cartographic data used in drawing a map and in conducting aroute search, guide data for visual/vocal route guidance, programs(i.e., applications and/or operating systems) for map display, routesearching, vocal guidance, and the like; a central processing unit 4serving as a navigation processing means for controlling all processesexecuted by the system, including map-display processing, route searchprocessing and visual/vocal route guidance processing, by reading outthe cartographic data from the information storing unit 3 or bytemporarily storing the cartographic data read out from the unit 3; aninformation transmit-receive unit 5 for transmitting/receiving roadinformation, traffic information, and detected information concerningthe present position of the vehicle; and an output unit 6 for outputtingthe route guidance.

[0029] According to the present embodiment, the central processing unit4 includes a control means 11 for displaying an input page from which anaddress is input as a hierarchical series of inputs (series ofadministrative levels) as well as for displaying an administrativedistrict name of a previously retrieved point in an administrativedistrict item field shown on the input page.

[0030]FIG. 2 illustrates an input page used in the embodiment of FIG. 1.

[0031] Upon selection of an address input menu from a menu page on themap display device, an input page is next displayed as shown in FIG.2(a). The input page shows administrative district item fields; forexample, from top to bottom, (1) “Administrative divisions of Japan”(the Tokyo metropolitan area, Hokkaido, and other prefectures), (2)“Cities, Towns and Villages”, (3) “Wards”, (4) “Ooaza, or a largehamlet,” (a large collection of dwellings), (5) “Koaza/Cho-me, or asmall hamlet” (a small collection of dwellings), (6) “Banchi, or Housenumber.” When any one of the hierarchical fields is clicked, the inputpage goes to an item input page for the selected level of the hierarchy(field), as shown in FIG. 2(b). The right side of the item input page isallocated for a description (i.e. name) of an administrative district.The administrative district names are preliminarily stored in theinformation storing unit 3. The number of the administrative districtitem fields (hierarchical levels) on the item input page ranges from 1to n. In the present embodiment as shown in FIG. 2(c), the number of thefields is exemplified by n=6. When the administrative district field 1is clicked, names of “Administrative divisions of Japan,” storedpreliminarily in the unit 3, are displayed in the form of a list in theorder of the Japanese syllables. In FIG. 2(c), for example,Aichi-prefecture is selected from the list of “Administrative divisionsof Japan” in the field 1. When the administrative district field 2 isclicked, names of “Cities, Towns, and Villages” are displayed in theform of a list in the order of the Japanese syllables. Then, the user isprompted to select his/her desired name from the list of “Cities, Towns,and Villages”. Here, “Nagoya-city” is selected from the list for thefield 2.

[0032] The foregoing embodiment, modified for use in the United Stateswould have 3 or 4 administrative item fields, i.e., state/city/streetaddress or state/city/zip code (or county)/street address. For example,where field 1 is clicked names of the different states would bedisplayed in the form of an alphabetical list. When field 2 is clicked,the names of cities within the selected state would be displayed inalphabetical order and when field 3 is clicked a screen for input of thestreet address would be displayed. Selection of a city (field 2) wouldbe prompted in the same manner as described above.

[0033] As described above, a click on a administrative district itemfield produces a list of administrative district names in that field(level) which are stored preliminarily in the information storing unit3. This list gives the user an opportunity to voluntary select and inputhis/her desired administrative district. According to the presentembodiment, every inputted address is cumulatively stored in the unit 3.Referring to such stored addresses of the retrieved points, as shown inFIG. 2(a), the input page in its initial state displays theadministrative district name that was input last time or theadministrative district name having been input the largest number oftimes.

[0034] Thus, it is possible to input an address using the input page inits initial state, without change of any administrative district nameshown on the input page. Alternatively, using the input page in itsinitial state, it is possible to input an address by changing anadministrative district name shown therein; for example, the addressinput may be effected by changing only names of “A large hamlet, orOoaza” (a large collection of dwellings) “A small hamlet, orKoaza/Cho-me” (a small collection of dwellings), and “House number, orBanchi,” while leaving unchanged names of “Administrative divisions ofJapan” (the Tokyo metropolitan area, Hokkaido, and other prefectures),“Cities, Towns and Villages”, and “Wards” as they are in their initialstate.

[0035]FIG. 3 is a flowchart showing a process of point retrieval basedon an address hierarchical structure according to the presentembodiment. As previously described with reference to FIG. 2, the inputpage in its initial state shows the administrative district name thatwas input last time or the administrative district name input thelargest number of times, from among other administrative district namesof previously retrieved points. Therefore, when the user wants toretrieve a new point whose address is similar to the address of thepreviously retrieved point, the retrieval of the new point is done,based on the input page in its initial state, by changing theadministrative district names shown in the administrative district itemfields “m” through “n” (Step 1). More specifically, when “m”=2, theadministrative district item fields 2 through n are subjected to namechange. When “m”=3, the administrative district item fields 3 through nare subject to name change. When “m”=n, only the administrative districtitem field n is subject to name change (Step 2). In other words, theinput of the new address can be arbitrarily started at anyadministration level (item field) of the display of the address of thepreviously retrieved point, and proceed therefrom to loweradministrative levels (smaller administrative units or districts). Whenthe administrative district item field is clicked, the administrativedistrict names are displayed in the form of a list in the order of theJapanese syllables on the right side of the item input page. Then, theuser is prompted to select his/her desired administrative district namefrom the list, whereby the address of the new point is input.

[0036] When input of the address of the point is finished, retrieval ofthe new point (coordinates of the new point) is started (Step 3). Afterthe new point is retrieved, data for the newly retrieved point, i.e.,data items for each administrative district name of the newly retrievedpoint in the fields 1 through n, is stored in the unit 3 (Step 4). Inother words, data related to the address of the newly retrieved point isstored in the unit 3 in a field-to-field (hierarchical) structure. Thishelps the user to input his/her desired address in a series ofadministrative district-to-district inputs, thus simplifying the processfor inputting an address of a point.

[0037]FIG. 4(a) shows the initial state of the input page. In itsinitial state, the left side of the input page displays a hierarchy ofdifferent administrative district levels (fields) while the right sideof the input page is blank. Here, the number of the administrativedistrict fields is six (n=6) and the fields 1 through 6 are presentedfor input of the administrative district names. As previously described,the input of the administrative district name in each field is done witha click. When an administrative field is clicked, the input page goes tothe item input page for that field. In this item input page, theadministrative district names are displayed in the form of a list on theright side. Then, the user is prompted to select his/her desired name ofthe administrative district from the list. This process of selection isrepeated to administrative district item field n, and thereby theaddress of a point is input. When the input of the address is finished,retrieval of the point (coordinates of the point) is started. After thepoint is retrieved, data for the retrieved point, i.e., each item ofdata for the administrative district names/retrieved points is stored inthe unit 3 in a field-to-field (hierarchical) structure.

[0038] For the next address input, the input page in its initial statedisplays, as shown in FIG. 4(b), the address that was input last timearound. The address input page in its initial state helps to simplifythe process of inputting a new address. For example, if the new addressdiffers slightly from a previously input address at the administrativedistrict level of “Ooaza, or a large hamlet,” (a large collection ofdwellings), “Koaza/Cho-me, or a small hamlet” (a small collection ofdwellings), and “Banchi, or House number,” the user is allowed to inputthe new address using the input page in its initial state, by changingonly the names of “Koaza/Cho-me, or a small hamlet” (a small collectionof dwellings), and “Banchi, or House number,” as shown in FIG. 4(d),while leaving unchanged the names of “Administrative divisions of Japan”(the Tokyo metropolitan area, Hokkaido, and other prefectures), “Cities,Towns and Villages”, and “Wards” just as they are in their initial stateas shown in FIG. 4(c). When input of the address is finished, retrievalof a point (coordinates of the point) is started. After the point isretrieved, data for the address of the retrieved point, i.e., the itemsof data for each administrative district name (level) of the retrievedpoint is stored in the unit 3 in hierarchical form (i.e., on anadministrative district-to-district basis).

[0039] To summarize, the map display device according to the presentinvention makes full use of the address that was input last time around,thus simplifying the process for inputting an address of a new pointlocated near the previously retrieved point whose address was input lasttime, thereby facilitating point retrieval.

[0040] According to the present invention, data for the address of everypreviously retrieved point is stored in administrativedistrict-to-district fields, i.e., in hierarchical form. Thiscontributes to a simplification of the point retrieval; in other words,simplification of both the process of inputting the administrativedistrict name and the process of selecting the administrative districtname from the list. The description which follows illustrates examplesof the simplified process for inputting the administrative district nameand for selecting administrative district names from the list.

[0041]FIG. 5 shows historic records of seven previously input addresses.As shown in FIG. 5, in the first use of the point retrieval system,“Shizuoka-prefecture, Hamamatsu-city, Shira-cho, Kuroyama 78” was input.In the second use of the point retrieval, “Aichi-prefecture, Anjo-city,Fujii-cho, Takane 10” was input. In the third and fourth application ofthe point retrieval, “Aichi-prefecture” was available from the addressinputted in the second application. In the fifth application of thepoint retrieval, both “Aichi-prefecture” and “Okazaki-city” wereavailable from the address input in the third application. In the sixthapplication of the point retrieval, “Aichi-prefecture,” “Nagoya-city,”and “Minami-ward” were available from the address input in the fourthapplication. In the seventh application of the point retrieval,“Aichi-prefecture” and “Nagoya-city” were available from the addressinput in the sixth application.

[0042]FIG. 6 illustrates data structure of the historic records of theinputted addresses of the previously retrieved points shown in FIG. 5.The data of the historic records takes the form of a tree-like structurein which data for the highest level administrative district is linked todata for lower level administrative districts (item fields). Forexample, “Aichi-prefecture” in the; administrative district field 1 islinked with “Nagoya-city,” “Okazaki-city,” and “Anjo-city” in theadministrative district item field 2. “Nagoya-city” in the field 2 islinked with “Midori-ward” and “Minami-ward” in the administrativedistrict field 3 “Okazaki-city” in the field 2 is linked with“Wakamatsu-cho” and “Oka-cho” in item field 3. “Anjo-city” in the field2 is linked with “Fujii-cho” in item field 3. In the same manner asabove, each item of data in field 3 is linked with data in theadministrative district item field 4. Likewise, the data in field 4 islinked with data in the administrative district item field 5.

[0043] Such a data structure eliminates duplication of the sameadministrative district names in storage, thereby saving memory space inthe map display device. This enables a limited memory space to storevoluminous historic records of the inputted addresses of the previouslyretrieved points.

[0044]FIG. 7 illustrates a routine for inputting an address of a pointto be retrieved based on the data structure shown in FIG. 6. FIG. 7(a)shows the initial state of the input page on which the historic recordsof the inputted address of the previously retrieved point are displayed.On this input page, a mark ▾ at the right end of the administrativedistrict item field indicates that the field has a plurality ofpreviously input administrative district names. In other words, the mark▾ indicates that the historic records of the input addresses of thepreviously retrieved points allow the user to select his/her desiredadministrative district name therefrom. In FIG. 7(a), “Aichi-prefecture”is selected for the field 1 of “Administrative divisions of Japan”. Whenthe field 2 of “Cities, Towns and Villages” is clicked, the previouslyinput administrative district names, “Nagoya-city,” “Okazaki-city,” and“Anjo-city” are listed on the right side of the item input page as shownin FIG. 7(b). When “Okazaki-city” is selected for the field 2, thepreviously input administrative district names for the field 3,“Wakamatsu-cho” and “Oka-cho,” are automatically listed as shown in FIG.7(c). When “Oka-cho” is selected for the field 3, in the same manner asabove, the previously input administrative district names for the field4 and the field 5 are sequentially displayed in the form of a list andthe user is prompted to select his/her desired administrative districtname from that list. Thus, the complete address is input as shown inFIG. 7(d).

[0045] In another example, when the field 1 of “Administrative divisionsof Japan” is clicked, the previously input administrative districtnames, “Aichi-prefecture” and “Shizuoka-prefecture,” are automaticallylisted on the right side of the item input page as shown in FIG. 7(e).When “Shizuoka-prefecture” is selected for the field 1, each of thelower administrative district names “Hamamatsu-city,” “Shira-cho,”“Kuroyama,” and “78,” are automatically and sequentially selected foreach lower administrative district item field. Thus, the whole addressis input as shown in FIG. 7(f). The automatic selection of theadministrative district names is based on the historic records of theinputted addresses of the previously retrieved points.

[0046] As mentioned above, in some cases, selection of the upperadministrative district name may cause automatic sequential input of thelower administrative district names based on the historic records of theinput addresses of the previously retrieved points. If there is aplurality of administrative district names for one field, they aredisplayed in the form of a list so that the user can select his/herdesired administrative district name from that list. If there is onlyone administrative district name for one field, it is automaticallyselected as the user-desired administrative district name and displayedin the field. Such automatic selection of the administrative districtname can simplify the process of inputting thee address.

[0047] In other cases, the selection of the upper administrativedistrict name is from a plurality of administrative district names forone lower administrative district item field below the selected upperadministrative district item field. In this case, the latest record ofthe input address of the previously retrieved point, i.e., theadministrative district name that was input last time around, isautomatically selected for the lower administrative district item field.If such lower administrative district name according to the latestrecord is unwanted by the user, the other administrative district namesfor the lower administrative district item field are displayed one byone in the order in which they were input for the point retrieval.

[0048] In a case where an attempt is made to exchange address databetween two computers that differ from each other, for example, betweena map display device and a personal computer, the difference between themap display device and the personal computer may cause lack ofdata-portability between them. For example, assume that data stored inthe personal computer is exported to the map display device. In thiscase, portability of the address data concerning the administrativedistrict names is sometimes lost while the portability of coordinatedata for the administrative districts is maintained.

[0049] In order to ensure full data-portability between differentsystems, as shown in FIG. 8, the data processing unit in the map displaydevice according to the present invention is designed to derive addressinformation from the coordinate data exported from other systems, forexample, a personal computer, a portable telephone, a navigation device,etc. The derived address information serving as the address data foradministrative district names is stored in the unit 3 and used ininputting the administrative district name into each administrativedistrict item field. In such a way, the address data, i.e., the addressinformation derived from the coordinate data, stored in other systemsmay be used in the map display device. This enhances the usefulness ofthe system of the present invention for inputting the address of a pointto be retrieved.

[0050]FIG. 9 illustrates another preferred embodiment of a process ofpoint retrieval based on addresses, according to the process of thepresent invention, involving the following steps.

[0051] To begin the process, a destination-setting button provided on amenu page displayed on the map display device is pressed (Step S11).When the menu page goes to the next page, a destination-selecting buttonprovided on that next page is pressed (Step S12). Upon pressing thedestination-selecting button, a registered point list showing historicrecords of input addresses of the previously retrieved points isdisplayed as shown in FIG. 9(a). Then, a desired registered point isselected from the list (Step S13). Upon selection of the desiredregistered point from the list, a map that covers an area including theselected registered point is displayed, as shown in FIG. 9(b) (StepS14). The map as shown in FIG. 9(b) is provided with the followingon-screen keys: a “Details” key for selecting display of a detailed map,a “Wide area” key for selecting display of a wide-area map, a “Back” keyby which the display is returned to a previous page, and a “Set” keywith which a destination is set.

[0052] In Step S15, a judgement is made whether the “Set” key has beenpressed. When it is judged that the “Set” key has been pressed, theprocess goes to Step S19 and the desired registered point (selected inStep S13) is set as a destination. When it is judged that “Set” key hasnot been pressed, a judgement is made whether the “Back” key has beenpressed (Step S16). If it is judged that “Back” key has been pressed,the display goes to the Japanese syllables input page as shown in FIG.9(c) (Step S17). For example, when “Aichi-prefecture, Anjo-city,Fujii-cho” is selected from the registered point list shown in FIG. 9(a)in Step S13, “Aichi-prefecture, Anjo-city, Fujii-cho” is automaticallydisplayed on the Japanese syllables input page as shown in FIG. 9(c). Ifthe user wants to retrieve another address by changing “Fujii-cho” to“Ogawa-cho” for example, the “Correct” key provided on the Japanesesyllables input page is operated to delete “Fujii-cho” on acharacter-by-character basis. When “Fujii-cho” is completely deleted,“Ogawa-cho” is inputted in hiragana characters (46 Japanese symbolswhich represent all sound combinations) from the Japanese syllablesinput page. Operation of the “Transliterate” key provided on theJapanese syllables input page causes “Ogawa-cho” in hiragana charactersto be transliterated into kanji characters (Chinese character). Afterpressing the “Transliterate” key, the display goes to another page asshown in FIG. 9(d) (Step S18) and then “Aichi-prefecture, Anjo-city,Ogawa-cho” is set as a destination (Step S19). Upon setting of thedestination, a route to the destination is searched (Step S20). Then,route guidance along the searched route is started (Step S21).

[0053] As understood from the above description of the second preferredprocess, the map display according to the present invention makes fulluse of historic records of the input addresses of the previouslyretrieved points, thus simplifying the process for inputting the addressof a point located near the previously retrieved point, and therebyfacilitating easy point retrieval.

[0054] The map display device according to the present invention may bean in-car map display device comprising present position detectionmeans, input means, and communication means, wherewith the followingprocesses are executed. When present position data, guide data, etc. aretransmitted from the in-car map display device to a information center,the center searches for a route and sends back the determined(“searched”) route together with guidance information therefor, etc., tothe in-car map display device. Upon receipt of the searched route, theguide information therefor, etc., the map display device outputs them tothe user.

[0055] The above-mentioned information center is provided with retrievalmeans, route search means, etc. contains cartographic data, addressdata, point data, and data for historic records of inputted address ofthe previously retrieved points stored in the form of the treelike chartas shown in FIG. 6. Receiving data related to point retrieval from thein-car map display device, the information center sends back to thein-car map display device, as shown in FIG. 7, information for an inputpage from which an address can be input based on an administrativehierarchy. Upon receipt of the information for the administrativedistricts from the information center, the in-car map display devicecalls up the input page. Upon clicking the left or right side of theadministrative district item field provided on the input page, theinformation center starts to retrieve the address data and the data forhistoric records of the input address of the previously retrieved point.Then, the center sends back the retrieved data to the in-car map displaydevice.

[0056] Thus, a point retrieval request from the in-car map displaydevice prompts the information center to retrieve data necessary for theaddress input through the in-car map display device, thereby simplifyingthe process for inputting the address and thereby enhancing theusefulness of the address input system.

[0057] Accordingly, the present invention provides a map display devicethat makes full use of historic records of the inputted addresses of thepreviously retrieved points, thereby simplifying the process ofinputting the address of a point located near a previously retrievedpoint and thereby facilitating easy point retrieval.

[0058] The invention may be embodied in other specific forms withoutdeparting from the spirit or essential characteristics thereof. Thepresent embodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed is:
 1. A map display device for retrieving a point at aninputted address and for displaying a map that covers the pointretrieved for the inputted address, comprising: storage means forstoring historic records of input addresses of previously retrievedpoints based on a hierarchy of levels of administrative districts;control means for displaying an input page from which an address isinput on the basis of said hierarchy of levels of administrativedistricts and for displaying at least one administrative district nameas a hierarchy of different administrative levels as item fields on saidinput page.
 2. The map display device according to claim 1, wherein theadministrative district name of the previously retrieved point is thatlast input.
 3. The map display device according to claim 1, wherein theadministrative district name of the previously retrieved point is thatlast input the greatest number of times among the administrativedistrict names of the previously retrieved points.
 4. The map displaydevice according to claim 1, wherein the address of the retrieved pointis that set as a destination.
 5. The map display device according toclaim 1 further comprising: selection means for selecting anadministrative district name of the previously retrieved point, andwherein, responsive to the selection of the administrative district nameof the previously retrieved point, names of lower level administrativedistricts below the selected administrative district are displayed bythe control means.
 6. The map display device according to claim 2further comprising: selection means for selecting an administrativedistrict name of the previously retrieved point, and wherein, responsiveto the selection of the administrative district name of the previouslyretrieved point, names of lower level administrative districts below theselected administrative district are displayed by the control means. 7.The map display device according to claim 3 further comprising:selection means for selecting an administrative district name of thepreviously retrieved point, and wherein, responsive to the selection ofthe administrative district name of the previously retrieved point,names of lower level administrative districts below the selectedadministrative district are displayed by the control means.
 8. The mapdisplay device according to claim 4 further comprising: selection meansfor selecting an administrative district name of the previouslyretrieved point, and wherein, responsive to the selection of theadministrative district name of the previously retrieved point, names oflower level administrative districts below the selected administrativedistrict are displayed by the control means.
 9. The map display deviceaccording to claim 1, wherein the control means displays the names ofthe administrative districts for the levels below the one level in theform of a list.
 10. The map display device according to claim 1, whereinthe control means displays the names of the administrative districts forthe levels below the one level in the form of administrative districtname.
 11. A map display device for retrieving a point at an inputtedaddress and for displaying a map that covers the point retrieved for theinput address, comprising: storage means for storing information for theretrieved point; and control means for reading out historic records ofthe input addresses of previously retrieved points and for displayingthem in the form of a list, and for responsive to selection of anaddress of a previously retrieved point from the list, displaying aninput page with an address of the selected previously retrieved pointdisplayed on the input page as a hierarchy of different administrativelevels.
 12. The map display device according to claim 11, wherein a mapthat covers the previously retrieved point at the selected address isdisplayed, and further wherein the map changes to the input pageresponsive to a request for a change of the selected address.
 13. Themap display device according to claim 11, wherein the stored informationfor the retrieved point is an address of a registered point.
 14. Amachine-readable medium encoded with a program for a map display devicefor retrieving a point at an inputted address and for displaying a mapthat covers the point retrieved for the inputted address, and encodedwith historic records of previously input addresses for retrievedpoints, arranged in a hierarchy of administrative district levels, andwherein said program comprises: displaying an input page for input of anaddress as a hierarchy of levels of administrative districts anddisplaying at least one administrative district name as a hierarchy ofdifferent administrative levels as item fields.
 15. A machine-readablemedium according to claim 14 wherein the encoded program furthercomprises: prompting selection of any one of the item fields of the oneadministrative district name of a previously retrieved point; anddisplaying names of administrative districts in item fields below theselected one item field.
 16. A machine-readable medium encoded with aprogram for a map display device for retrieving a point at an inputaddress and for displaying a map that covers the point retrieved for theinputted address, and with information for the retrieved point whereinsaid program comprises: retrieving historic records of input addressesfor previously retrieved points; displaying the retrieved historicrecords in the form of a list for selection of an address of apreviously retrieved point; displaying an input page showing a selectedpreviously retrieved point with its address presented on the input pageas a hierarchy of different administrative levels; prompting selectionof any one of the administrative levels of the one administrativedistrict name of a previously retrieved point; and displaying names ofadministrative levels below the selected one administrative level.